GENERAL KNOWLEDGE

Detailed explanation-1: -Joseph Priestley (1733-1804)-Unitarian minister, teacher, author, and natural philosopher-was the Earl of Shelburne’s librarian and tutor to his sons. In this room, then a working laboratory, Priestley pursued his investigations of gases. On 1 August 1774 he discovered oxygen.

Detailed explanation-2: -Some historians argue that credit for discovering oxygen should go to the Swedish chemist Carl Scheele, who identified it several years before Priestley.

Detailed explanation-3: -Priestley was one of the first scientists who discovered oxygen. In 1774, he prepared oxygen by heating mercury oxide with a burning glass. He found that oxygen did not dissolve in water and it made combustion stronger. Priestley was a firm believer of phlogiston theory.